In positron emission tomography (pet), a positron collides with an electron and the two particles disappear in a burst of a) an alpha particle and a gamma ray. b) two beta particles. c) a neutron and an alpha particle. d) two gamma rays

Why do scientists believe that light is made of streams of particles? scientists believe that light is made of streams of particles because only the presence of photons can explain phenomena observed during experiments on the photoelectric effect. these observations include only some frequencies of light causing the ejection of electrons, no time gap existing between light striking a metal and electrons being ejected, and intensity having no effect on the kinetic energy of the ejected electrons.

Um vetor representa um deslocamento cujo módulo é 20 m. se v faz um ângulo de 60 graus com a horizontal, qual é o valor das componentes horizontal e vertical deste vetor?

A51 kg woman skis down a hill and her kinetic energy is 9.96e4 j. what is her speed?